Potential Effects of Anthropogenic Climate Change on Non-Synoptic Wind Storm Hazards

One of the primary contributors to non-synoptic wind storms (NSWSs) is thunderstorm-induced phenomena such as tornadoes and downbursts. The intensity of these phenomena is intimately linked to the characteristics of their parent thunderstorms. In turn, these depend to varying degrees on the larger scale temperature, humidity, and winds, which comprise the meteorological environment of the NSWSs. Thus, any modification of the meteorological (and also physical-geographical) environment, be it natural or anthropogenic, has the potential to affect the intensity of NSWSs. This chapter begins with the background theory of how tornadoes and downbursts, specifically, relate to their larger scale environment. Simple arguments are then made on how changes to the environment might result in changes in the intensity and other characteristics of tornadoes and downbursts. Next, analyses of historical data are examined to determine the existence of any long-term trends in such intensity/characteristics consistent with an ongoing anthropogenic climate change impact. To determine if future impacts are to be expected, global and regional climate model simulations are consulted; a discussion of the means in which these simulations are “downscaled” to thunderstorm (and smaller) scales is provided here. The chapter concludes with some insight into implications of the historical and projected trends on exposure and risk to NSWSs.